End Effector With Redundant Closing Mechanisms

ABSTRACT

End effectors with redundant closing mechanisms, and related tools and methods are disclosed. The disclosed end effectors may be particularly beneficial when used for minimally invasive surgery. An example surgical tool comprises an elongate shaft having a proximal end and a distal end, a tool body disposed at the distal end of the shaft, a jaw movable relative to the tool body between a clamped configuration and an open configuration, a first actuation mechanism coupled with the jaw and operable to vary the position of the jaw relative to the tool body between the clamped configuration and the open configuration, and a second actuation mechanism coupled with the jaw. The second actuation mechanism has a first configuration where the jaw is held in the clamped configuration and a second configuration where the position of the jaw relative to the tool body is unconstrained by the second actuation mechanism.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/519,908 filed Oct. 21, 2014 (Allowed); which is a divisional of U.S.application Ser. No. 12/945,541 filed Nov. 12, 2010 (now U.S. Pat. No.8,876,857); which claims the benefit under 35 U.S.C. §119(e) of U.S.Provisional Application No. 61/260,907 filed Nov. 13, 2009; thedisclosures of which are incorporated herein by reference.

This application is also related to U.S. application Ser. No. 12/945,730filed Nov. 12, 2010 (Allowed); U.S. application Ser. No. 12/945,740filed Nov. 12, 2010; U.S. application Ser. No. 12/945,748 filed Nov. 12,2010 (now U.S. Pat. No. 8,852,174); and U.S. application Ser. No.12/945,461 filed Nov. 12, 2010 (now U.S. Pat. No. 8,640,788); the fulldisclosures of which are incorporated herein by reference.

BACKGROUND

Minimally invasive surgical techniques are aimed at reducing the amountof extraneous tissue that is damaged during diagnostic or surgicalprocedures, thereby reducing patient recovery time, discomfort, anddeleterious side effects. As a consequence, the average length of ahospital stay for standard surgery may be shortened significantly usingminimally invasive surgical techniques. Also, patient recovery times,patient discomfort, surgical side effects, and time away from work mayalso be reduced with minimally invasive surgery.

A common form of minimally invasive surgery is endoscopy, and a commonform of endoscopy is laparoscopy, which is minimally invasive inspectionand surgery inside the abdominal cavity. In standard laparoscopicsurgery, a patient's abdomen is insufflated with gas, and cannulasleeves are passed through small (approximately one-half inch or less)incisions to provide entry ports for laparoscopic instruments.

Laparoscopic surgical instruments generally include an endoscope (e.g.,laparoscope) for viewing the surgical field and tools for working at thesurgical site. The working tools are typically similar to those used inconventional (open) surgery, except that the working end or end effectorof each tool is separated from its handle by an extension tube (alsoknown as, e.g., an instrument shaft or a main shaft). The end effectorcan include, for example, a clamp, grasper, scissor, stapler, cauterytool, linear cutter, or needle holder.

To perform surgical procedures, the surgeon passes working tools throughcannula sleeves to an internal surgical site and manipulates them fromoutside the abdomen. The surgeon views the procedure by means of amonitor that displays an image of the surgical site taken from theendoscope. Similar endoscopic techniques are employed in, for example,arthroscopy, retroperitoneoscopy, pelviscopy, nephroscopy, cystoscopy,cisternoscopy, sinoscopy, hysteroscopy, urethroscopy, and the like.

Minimally invasive telesurgical robotic systems are being developed toincrease a surgeon's dexterity when working on an internal surgicalsite, as well as to allow a surgeon to operate on a patient from aremote location (outside the sterile field). In a telesurgery system,the surgeon is often provided with an image of the surgical site at acontrol console. While viewing a three dimensional image of the surgicalsite on a suitable viewer or display, the surgeon performs the surgicalprocedures on the patient by manipulating master input or controldevices of the control console. Each of the master input devicescontrols the motion of a servo-mechanically actuated/articulatedsurgical instrument. During the surgical procedure, the telesurgicalsystem can provide mechanical actuation and control of a variety ofsurgical instruments or tools having end effectors that perform variousfunctions for the surgeon, for example, holding or driving a needle,grasping a blood vessel, dissecting tissue, or the like, in response tomanipulation of the master input devices.

Non-robotic linear clamping, cutting and stapling devices have beenemployed in many different surgical procedures. For example, such adevice can be used to resect a cancerous or anomalous tissue from agastro-intestinal tract. Unfortunately, many known surgical devices,including known linear clamping, cutting and stapling devices, haveopposing jaws that may generate less than a desired clamping force,which may reduce the effectiveness of the surgical device. Alternativedevices may provide sufficient mechanical advantage to generate adesired level of clamping force for applicable surgical procedures(e.g., tissue stapling), but may have an actuation response rate that isless than desirable for telesurgical tissue manipulation. Furthermore,swapping tools having such high force jaw actuation mechanisms may bemore complex (and potentially more prone to glitches) than would beideal.

Thus, there is believed to be a need for tools with improved endeffectors. Improved end effectors that provide sufficient clampingforce, provide a fast response/low force articulation mode, and are atleast partially back-drivable may also be desirable. Such tools may bebeneficial in surgical applications, particularly in minimally invasivesurgical applications.

BRIEF SUMMARY

Improved end effectors, related tools, and related methods are provided.In many surgical applications, for example, many minimally invasivesurgical applications, the size of a surgical tool end effector issubstantially constrained by applicable space constraints. While such asize constraint mitigates in favor of the use of one actuationmechanism, in many embodiments, the disclosed end effectors use twoindependent mechanisms to articulate a jaw of the end effector. In manyembodiments, a first actuation mechanism provides a fast response/lowforce mode that varies the position of the articulated jaw between aclamped configuration and an open configuration. In many embodiments,the first actuation mechanism is back-drivable. In many embodiments, asecond actuation mechanism provides a high clamping force mode that hasa first configuration where the articulated jaw is held in a clampedconfiguration and a second configuration where the articulated jaw isunconstrained by the second actuation mechanism. In many embodiments,the second actuation mechanism is non-back-drivable.

Such end effectors, tools, and methods provide a number of benefits,particularly with respect to minimally invasive surgical applications.For example, in many embodiments, the high clamping force articulationmode enables proper tissue compression and resists jaw motion, forexample, during staple firing. In many embodiments, the fastresponse/low force mode is useful for manipulating tissue, is useful forfinding a more optimum tissue purchase, and provides a more responsivearticulation of the articulated jaw. In many embodiments, aback-drivable first actuation mechanism permits the articulated jaw tomove upon heavy contact with patient tissue, which may help to avoidinjuring the patient tissue, and/or permits the articulated jaw to closeupon contact with a cannula sleeve, which may aid in the removal of thesurgical tool from the patient. Additionally, the disclosed endeffectors may provide for improved tissue gap and/or tissue compressionsensing because the redundant actuation mechanisms may provideadditional feedback data for analysis and, in many embodiments, thefirst actuation mechanism can be made to function efficiently with lowfrictional losses, which may improve sensing capability. While thevarious embodiments disclosed herein are primarily described with regardto surgical applications, these surgical applications are merely exampleapplications, and the disclosed end effectors, tools, and methods can beused in other suitable applications, both inside and outside a humanbody, as well as in non-surgical applications.

In a first aspect, a minimally invasive surgical method is provided. Themethod includes introducing a jaw of a tool to an internal surgical sitewithin a patient through a minimally invasive aperture or naturalorifice, manipulating tissue at the internal surgical site with agrasping force by articulating the jaw with a first actuation mechanism,and treating a target tissue at the internal surgical site using aclamping force by articulating the jaw of the tool with a secondactuation mechanism. The first and second actuation mechanisms extendalong a shaft from outside the patient to the jaw. The clamping force isgreater than the grasping force.

In many embodiments, the first actuation mechanism comprises cablesegments and the second actuation mechanism comprises a drive shaft. Inmany embodiments, the manipulation of the tissue is performed by closingthe jaw using tension in a first cable segment and by opening the jawusing tension in a second cable segment. In many embodiments, thetreatment of the tissue is performed by closing the jaw using a rotationof the drive shaft within the shaft of the tool. In many embodiments,the second actuation mechanism back-drives the first mechanism such thatarticulation of the second actuation mechanism to close the jaw willdrive the cable segments toward a closed jaw configuration andarticulation of the second actuation mechanism toward an open jawconfiguration will not back-drive the first mechanism or open the jaw ifthe cable segments remain in a closed jaw configuration.

In another aspect, a surgical tool is provided. The tool includes anelongate shaft having a proximal end and a distal end, a tool bodydisposed at the distal end of the shaft, a jaw movable relative to thetool body between a clamped configuration and an open configuration, afirst actuation mechanism coupled with the jaw, and a second actuationmechanism coupled with the jaw. The first actuation mechanism isoperable to vary the position of the jaw relative to the tool bodybetween the clamped configuration and the open configuration. The secondactuation mechanism has a first configuration in which the jaw is heldin the clamped configuration and a second configuration in which theposition of the jaw relative to the tool body is unconstrained by thesecond actuation mechanism.

The first actuation mechanism can include one or more additionalcomponents and/or have one or more additional characteristics. Forexample, in many embodiments, the first actuation mechanism isback-drivable. In many embodiments, the first actuation mechanismincludes cables. In many embodiments, a pulling movement of a firstcable segment of the first actuation mechanism moves the jaw towards theopen configuration and a pulling movement of a second cable segment ofthe first actuation mechanism moves the jaw towards the clampedconfiguration. The first actuation mechanism can include a first linkagecoupling the first cable segment with the jaw and the tool body. Thefirst actuation mechanism can include a second linkage coupling thesecond cable segment with the jaw and the tool body.

The second actuation mechanism can include one or more additionalcomponents and/or have one or more additional characteristics. Forexample, in many embodiments, the second actuation mechanism isnon-back-drivable. The second actuation mechanism can be operable toproduce a clamping force between the jaw and the tool body of at least20 lbs. In many embodiments, the second actuation mechanism includes aleadscrew. The second actuation mechanism can include a leadscrew drivencam operatively coupled with the leadscrew and the jaw can include aninterfacing cam surface for contact with the leadscrew driven cam.

The surgical tool can include one or more additional components. Forexample, the surgical tool can further include an actuated device. Forexample, the actuated device can be a cutting device, a stapling device,or a cutting and stapling device.

In another aspect, a robotic tool is provided for mounting on amanipulator having a first drive. The robotic tool includes a proximaltool chassis releasably mountable to the manipulator; a drive motorcoupled with the tool chassis and disposed adjacent the tool chassis; adistal end effector comprising a movable jaw; an instrument shaft havinga proximal end adjacent the chassis, and a distal end adjacent the endeffector; a first actuation mechanism coupling the first drive to theend effector when the chassis is mounted to the manipulator so as toarticulate the end effector between an open configuration and a clampedconfiguration; and a second actuation mechanism coupling the drive motorto the end effector so as to articulate the end effector into theclamped configuration from the open configuration.

The first actuation mechanism can include one or more additionalcomponents and/or have one or more additional characteristics. Forexample, in many embodiments, the first actuation mechanism isback-drivable. The first actuation mechanism can include cablesextending from the chassis distally within a bore of the instrumentshaft operatively coupling the end effector to the first drive.

The second actuation mechanism can include one or more additionalcomponents and/or have one or more additional characteristics. Forexample, in many embodiments, the second actuation mechanism isnon-back-drivable. The second actuation mechanism can include aleadscrew driven cam. The second actuation mechanism can have a firstconfiguration where the jaw is held in the clamped configuration and asecond configuration where the position of the jaw relative to the toolbody is unconstrained by the second actuation mechanism. The secondactuation mechanism can include a drive shaft mounted for rotationwithin a bore of the instrument shaft and operatively coupling the endeffector to the drive motor.

In another aspect, a surgical instrument is provided. The surgicalinstrument includes an end effector comprising a movable jaw, a firstjaw actuation mechanism coupled to the movable jaw, and a second jawactuation mechanism coupled to the moveable jaw. The first jaw actuationmechanism moves the jaw from an open position to a closed positionindependently of the second jaw actuation mechanism. The second jawactuation mechanism moves the jaw from the open position to the closedposition independently of the first jaw actuation mechanism.

The second jaw mechanism can constrain the range of motion in which thefirst actuation mechanism can move the jaw. For example, the secondactuation mechanism can have a first configuration in which the movablejaw is held in a clamped position and in which the first actuationmechanism is prevented from moving the movable jaw.

The first actuation mechanism can provide a fast response/low forcearticulation mode, and the second actuation mechanism can provide a highclamping force mode. For example, in many embodiments, the maximumclamping force of the movable jaw provided by the second actuationmechanism is larger that a maximum clamping force provided by the firstactuation mechanism.

The first and second actuation mechanisms can employ different forcetransmission mechanisms. For example, a force used by the first jawactuation mechanism to move the jaw from the open to the close positioncan include a linear force, and a force used by the second jaw actuationmechanism to move the jaw from the open to the closed position caninclude a torque. In many embodiments, the first jaw actuation mechanismincludes a cable-driven mechanism. In many embodiments, the second jawactuation mechanism includes a leadscrew-driven mechanism.

For a fuller understanding of the nature and advantages of the presentinvention, reference should be made to the ensuing detailed descriptionand accompanying drawings. Other aspects, objects and advantages of theinvention will be apparent from the drawings and detailed descriptionthat follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a minimally invasive robotic surgery systembeing used to perform a surgery, in accordance with many embodiments.

FIG. 2 is a perspective view of a surgeon's control console for arobotic surgery system, in accordance with many embodiments.

FIG. 3 is a perspective view of a robotic surgery system electronicscart, in accordance with many embodiments.

FIG. 4 diagrammatically illustrates a robotic surgery system, inaccordance with many embodiments.

FIG. 5A is a front view of a patient side cart (surgical robot) of arobotic surgery system, in accordance with many embodiments.

FIG. 5B is a front view of a robotic surgery tool.

FIG. 6A is a perspective view of an end effector having an articulatedjaw, in accordance with many embodiments.

FIG. 6B is a perspective view of the end effector of FIG. 6A (with thearticulated jaw removed to better illustrate leadscrew actuationmechanism components), in accordance with many embodiments.

FIGS. 7A and 7B illustrate components of a leadscrew actuationmechanism, in accordance with many embodiments.

FIG. 8A illustrates components of a cable actuation mechanism, inaccordance with many embodiments.

FIG. 8B is a perspective view of the end effector of FIG. 8A with aportion of the articulated jaw removed to show cable actuation mechanismcomponents disposed behind the articulated jaw, in accordance with manyembodiments.

FIGS. 8C through 8F illustrate opposite side components of the cableactuation mechanism of FIG. 8A.

FIG. 9A is a perspective view illustrating a cable actuation mechanism,showing a cable used to articulate the jaw towards a clampedconfiguration, in accordance with many embodiments.

FIG. 9B is a perspective view illustrating the cable actuation mechanismof FIG. 9A, showing a cable used to articulate the jaw towards an openconfiguration.

FIG. 10 is a cross-sectional view illustrating components of a leadscrewactuation mechanism, in accordance with many embodiments.

FIG. 11 is a simplified diagrammatic illustration of a tool assembly, inaccordance with many embodiments.

FIG. 12 is a simplified diagrammatic illustration of a robotic toolmounted to a robotic tool manipulator, in accordance with manyembodiments.

DETAILED DESCRIPTION

Improved end effectors, related tools, and related methods are provided.In many embodiments, the disclosed end effectors use two independentmechanisms to articulate a jaw of the end effector. In many embodiments,a first actuation mechanisms provides a fast response/low force modethat varies the position of the articulated jaw between a clampedconfiguration and an open configuration. In many embodiments, the firstactuation mechanism is back-drivable. The first actuation mechanism canbe designed to provide, for example, 5 lbs of clamping force at the tipof the articulated jaw of the end effector. In many embodiments, asecond actuation mechanism provides a high clamping force mode that hasa first configuration where the articulated jaw is held in a clampedconfiguration and a second configuration where the articulated jaw isunconstrained by the second actuation mechanism. In many embodiments,the second actuation mechanism is non-back-drivable. In manyembodiments, the second actuation mechanism converts a relatively weakforce or torque (but with large displacement available) to a relativelyhigh torque rotating the jaw of the end effector. The second actuationmechanism can be designed to provide, for example, 50 pounds of clampingforce at the tip of the articulated jaw of the end effector. Thedisclosed end effectors, tools, and methods can be used in a variety ofapplications, and may be particularly beneficial when used in minimallyinvasive surgery applications. While the various embodiments disclosedherein are primarily described with regard to surgical applications,these surgical applications are merely example applications, and thedisclosed end effectors, tools, and methods can be used in othersuitable applications, both inside and outside a human body, as well asin non-surgical applications.

Minimally Invasive Robotic Surgery

Referring now to the drawings, in which like reference numeralsrepresent like parts throughout the several views, FIG. 1 is a plan viewillustration of a Minimally Invasive Robotic Surgical (MIRS) system 10,typically used for performing a minimally invasive diagnostic orsurgical procedure on a Patient 12 who is lying down on an Operatingtable 14. The system can include a Surgeon's Console 16 for use by aSurgeon 18 during the procedure. One or more Assistants 20 may alsoparticipate in the procedure. The MIRS system 10 can further include aPatient Side Cart 22 (surgical robot), and an Electronics Cart 24. ThePatient Side Cart 22 can manipulate at least one removably coupled toolassembly 26 (hereinafter simply referred to as a “tool”) through aminimally invasive incision in the body of the Patient 12 while theSurgeon 18 views the surgical site through the Console 16. An image ofthe surgical site can be obtained by an endoscope 28, such as astereoscopic endoscope, which can be manipulated by the Patient SideCart 22 so as to orient the endoscope 28. The Electronics Cart 24 can beused to process the images of the surgical site for subsequent displayto the Surgeon 18 through the Surgeon's Console 16. The number ofsurgical tools 26 used at one time will generally depend on thediagnostic or surgical procedure and the space constraints within theoperating room among other factors. If it is necessary to change one ormore of the tools 26 being used during a procedure, an Assistant 20 mayremove the tool 26 from the Patient Side Cart 22, and replace it withanother tool 26 from a tray 30 in the operating room.

FIG. 2 is a perspective view of the Surgeon's Console 16. The Surgeon'sConsole 16 includes a left eye display 32 and a right eye display 34 forpresenting the Surgeon 18 with a coordinated stereo view of the surgicalsite that enables depth perception. The Console 16 further includes oneor more input control devices 36, which in turn cause the Patient SideCart 22 (shown in FIG. 1) to manipulate one or more tools. The inputcontrol devices 36 will provide the same degrees of freedom as theirassociated tools 26 (shown in FIG. 1) so as to provide the Surgeon withtelepresence, or the perception that the input control devices 36 areintegral with the tools 26 so that the Surgeon has a strong sense ofdirectly controlling the tools 26. To this end, position, force, andtactile feedback sensors (not shown) may be employed to transmitposition, force, and tactile sensations from the tools 26 back to theSurgeon's hands through the input control devices 36.

The Surgeon's Console 16 is usually located in the same room as thepatient so that the Surgeon may directly monitor the procedure, bephysically present if necessary, and speak to an Assistant directlyrather than over the telephone or other communication medium. However,the Surgeon can be located in a different room, a completely differentbuilding, or other remote location from the Patient allowing for remotesurgical procedures (i.e., operating from outside the sterile field).

FIG. 3 is a perspective view of the Electronics Cart 24. The ElectronicsCart 24 can be coupled with the endoscope 28 and can include a processorto process captured images for subsequent display, such as to a Surgeonon the Surgeon's Console, or on any other suitable display locatedlocally and/or remotely. For example, where a stereoscopic endoscope isused, the Electronics Cart 24 can process the captured images so as topresent the Surgeon with coordinated stereo images of the surgical site.Such coordination can include alignment between the opposing images andcan include adjusting the stereo working distance of the stereoscopicendoscope. As another example, image processing can include the use ofpreviously determined camera calibration parameters so as to compensatefor imaging errors of the image capture device, such as opticalaberrations.

FIG. 4 diagrammatically illustrates a robotic surgery system 50 (such asMIRS system 10 of FIG. 1). As discussed above, a Surgeon's Console 52(such as Surgeon's Console 16 in FIG. 1) can be used by a Surgeon tocontrol a Patient Side Cart (Surgical Robot) 54 (such as Patient SideCart 22 in FIG. 1) during a minimally invasive procedure. The PatientSide Cart 54 can use an imaging device, such as a stereoscopicendoscope, to capture images of the procedure site and output thecaptured images to an Electronics Cart 56 (such as the Electronics Cart24 in FIG. 1). As discussed above, the Electronics Cart 56 can processthe captured images in a variety of ways prior to any subsequentdisplay. For example, the Electronics Cart 56 can overlay the capturedimages with a virtual control panel interface prior to displaying thecombined images to the Surgeon via the Surgeon's Console 52. The PatientSide Cart 54 can output the captured images for processing outside theElectronics Cart 56. For example, the Patient Side Cart 54 can outputthe captured images to a processor 58, which can be used to process thecaptured images. The images can also be processed by a combination theElectronics Cart 56 and the processor 58, which can be coupled togetherso as to process the captured images jointly, sequentially, and/orcombinations thereof. One or more separate displays 60 can also becoupled with the processor 58 and/or the Electronics Cart 56 for localand/or remote display of images, such as images of the procedure site,or any other related images.

FIGS. 5A and 5B show a Patient Side Cart 22 and a surgical tool 62,respectively. The surgical tool 62 is an example of the surgical tools26. The Patient Side Cart 22 shown provides for the manipulation ofthree surgical tools 26 and an imaging device 28, such as a stereoscopicendoscope used for the capture of images of the site of the procedure.Manipulation is provided by robotic mechanisms having a number ofrobotic joints. The imaging device 28 and the surgical tools 26 can bepositioned and manipulated through incisions in the patient so that akinematic remote center is maintained at the incision so as to minimizethe size of the incision. Images of the surgical site can include imagesof the distal ends of the surgical tools 26 when they are positionedwithin the field-of-view of the imaging device 28.

End Effector Jaw Articulation with Independent Actuation Mechanisms

In many embodiments, two independent actuation mechanisms are used tocontrol the articulation of an articulated jaw of an end effector. Afirst actuation mechanism can be used to provide a fast response/lowforce mode, and a second actuation mechanism can be used to provide ahigh clamping force mode. In many embodiments, the first actuationmechanism used to provide the fast response/low force articulation modeis back-drivable. In many embodiments, the second actuation mechanismused to provide the high clamping force articulation mode isnon-back-drivable. Such use of two independent actuation mechanisms maybe beneficial in some surgical applications, for example, electrocauterysealing, stapling, etc., that may require multiple low force jawplacement clampings before a high force jaw clamping is used to carryout the surgical tool's task.

In many embodiments, the fast response/low force mode is provided by acable actuation mechanism that includes a pair of pull cables. In manyembodiments, a pulling motion of a first cable of the pair articulatesthe articulated jaw towards a closed (clamped) configuration and apulling motion of a second cable of the pair articulates the articulatedjaw towards an open configuration. In many embodiments, the cableactuation mechanism is back-drivable.

In many embodiments, the high clamping force mode is provided by aleadscrew actuation mechanism that includes a leadscrew driven cam. Thedriven cam interfaces with a mating cam surface on the articulated jawso as to hold the articulated jaw in a clamped configuration when theleadscrew driven cam is at a first end of its range of motion. Inaddition, the driven cam does not constrain motion of the articulatedjaw when the leadscrew driven cam is at a second end (opposite end) ofits range of motion. In other words, the mating cam surfaces arearranged such that motion of the leadscrew driven cam in one directionwill cause the articulated jaw to close, and motion of the leadscrewdriven cam in the reverse direction will allow (but not force) thearticulated jaw to open to a limit provided by the cam surfaces. In manyembodiments, the leadscrew actuation mechanism is non-back-drivable.

FIG. 6A is a perspective view of an end effector 70 having a jaw 72articulated by two independent actuation mechanisms, in accordance withmany embodiments. The end effector 70 includes an end effector base 74,the articulated jaw 72, and a detachable stationary jaw 76. The endeffector 70 is actuated via a first drive shaft 78, a second drive shaft80, and two actuation cables (not shown). The first drive shaft 78rotates a leadscrew 82 of a leadscrew actuation mechanism. The seconddrive shaft 80 rotates another leadscrew (not shown) of the detachablestationary jaw 76.

In many embodiments, the first drive shaft 78 and/or the second driveshaft 80 are driven by drive features located in a proximal tool chassisto which the end effector 70 is coupled with via an instrument shaft. Inmany embodiments, the proximal tool chassis is configured to bereleasably mountable to a robotic tool manipulator. In many embodiments,the first drive shaft 78 and the second drive shaft 80 are actuated viarespective drive features located in the proximal tool chassis. In manyembodiments, such drive features are driven by motors that are locatedin the proximal tool chassis.

FIG. 6B is a perspective view of the end effector 70 of FIG. 6A (withthe articulated jaw 72 removed to better illustrate components of theleadscrew actuation mechanism), in accordance with many embodiments. Theleadscrew 82 is mounted for rotation relative to the end effector base74. A leadscrew driven cam 84 is coupled with the leadscrew 82 so thatselective rotation of the leadscrew 82 can be used to selectivelytranslate the leadscrew driven cam 84 along a cam slot 86 in the endeffector base 74. The end effector 70 includes a pivot pin 88 that isused to rotationally couple the articulated jaw 72 with the end effectorbase 74.

FIGS. 7A and 7B illustrate the leadscrew actuation mechanism of FIGS. 6Aand 6B. The leadscrew 82 has a distal journal surface 96 and a proximaljournal surface that interfaces with a proximal bearing 98. In manyembodiments, the distal journal surface 96 is received within acylindrical receptacle located at the distal end of the cam slot 86.Such a distal support for the leadscrew 82 can be configured to keep theleadscrew 82 from swinging excessively, and with relatively largeclearance(s) between the distal journal surface 96 and the cylindricalreceptacle. The proximal bearing 98 is supported by the end effectorbase 74 so as to support the proximal end of the leadscrew 82. Theproximal bearing 98 can be a ball bearing, which may help to reducefriction and wear. A distal bearing (not shown) can be supported by theend effector base 74 so as to support the distal end of the leadscrew82, and the distal bearing can be a ball bearing. The leadscrew drivencam 84 includes a threaded bore configured to mate with the externalthreads of the leadscrew 82. The leadscrew driven cam 84 includes topand bottom surfaces configured to interact with corresponding top andbottom surfaces of the cam slot 86. The interaction between leadscrewdriven cam 84 and the cam slot 86 prevents the leadscrew driven cam 84from rotating relative to the cam slot 86, which causes the leadscrewdriven cam 84 to translate along the cam slot 86 in response to rotationof the leadscrew.

The articulated jaw 72 includes mating cam surfaces 94 that areconfigured so that the position of the leadscrew driven cam 84 along thecam slot 86 determines the extent to which the rotational motion of thearticulated jaw 72 around the pivot pin 88 is constrained by theleadscrew driven cam 84. The articulated jaw 72 includes a firstproximal side 100 and a second proximal side 102 that are separated by acentral slot. The first and second proximal sides are disposed onopposing sides of the end effector base 74 when the articulated jaw 72is coupled with the end effector base 74 via the pivot pin 88. Each ofthe first and second proximal sides 100, 102 includes a recessed areadefining a mating cam surface 94 and providing clearance between theleadscrew driven cam 84 and the proximal sides 100, 102. When theleadscrew driven cam 84 is positioned at or near the proximal end of thecam slot 86 (near its position illustrated in FIGS. 7A and 7B), contactbetween the leadscrew driven cam 84 and the mating cam surfaces 94 ofthe articulated jaw 72 hold the articulated jaw in a clampedconfiguration. When the leadscrew driven cam 84 is positioned at thedistal end of the cam slot 86, the rotational position of thearticulated jaw around the pivot pin 88 is unconstrained by theleadscrew driven cam 84 for a range of rotational positions between aclamped configuration (where there is a gap between the leadscrew drivencam 84 and the mating cam surfaces 94 of the articulated jaw 72) and anopen configuration (where there may or may not be a gap between theleadscrew driven cam 84 and the mating cam surfaces 94 of thearticulated jaw 72). For positions of the leadscrew driven cam 84 inbetween the proximal and distal ends of the cam slot 86, the range ofunconstrained motion can vary according to the cam surfaces used.

The use of a recess in each of the proximal sides 100, 102 to define themating cam surfaces 94 of the articulated jaw 72 provides a number ofbenefits. For example, the use of recesses as opposed to traverse slotsthat extend through the proximal sides provides a continuous outsidesurface to the proximal sides 100, 102 of the articulated jaw, which isless likely to snag on patient tissue than would a traverse slotopening. The absence of traverse slots also helps to stiffen theproximal sides 100, 102 as compared to proximal sides with traverseslots, and therefore provides increased clamping stiffness. Suchproximal sides 100, 102 may have increased stiffness in two planes,which may help maintain alignment of the articulated jaw 72 in thepresences of external forces. Such increased stiffness in two planes maybe beneficial in some surgical applications, for example, in tissuestapling where it is beneficial to maintain alignment between thestaples and anvil pockets that form the staples. Further, the use ofrecesses instead of traverse slots also provides an actuation mechanismthat is less likely to be jammed by extraneous material as compared toone having proximal sides with open traverse slots.

The leadscrew actuation mechanism can be configured to provide a desiredclamping force between the articulated jaw and an opposing jaw of theend effector. For example, in many embodiments, the leadscrew actuationmechanism is configured to provide at least 20 lbs of clamping force atthe tip of the articulated jaw 72 (approximately 2 inches from the pivotpin 88). In many embodiments, the leadscrew actuation mechanism isconfigured to provide at least 50 lbs of clamping force at the tip ofthe articulated jaw 72. In many embodiments, to produce 50 lbs ofclamping force at the tip of the articulated jaw 72, the input torque tothe leadscrew 82 is approximately 0.2 N m and the leadscrew 82 has 29turns.

The leadscrew actuation mechanism can be fabricated using availablematerials and components. For example, many components of the leadscrewactuation mechanism can be fabricated from an available stainlesssteel(s). The leadscrew driven cam 84 can be coated (e.g., TiN) toreduce friction against the surfaces it rubs against (e.g., leadscrew82; end effector base 74; proximal sides 100, 102 of the articulated jaw72). Stranded cables can be used to drive the first actuation mechanism.

FIGS. 8A through 8F illustrate components of a cable actuation mechanism110, in accordance with many embodiments. As described above, theleadscrew driven cam 84 can be positioned at the distal end of the camslot 86 (i.e., near the pivot pin 88). For such a distal position of theleadscrew driven cam 84, as discussed above, the rotational position ofthe articulated jaw 72 about the pivot pin 88 is unconstrained for arange of rotational positions of the articulated jaw 72. Accordingly,the rotational position of the articulated jaw 72 about the pivot pin 88can be controlled by the cable actuation mechanism 110. The cableactuation mechanism 110 is operable to vary the rotational position ofthe articulated jaw between the clamped configuration and the openconfiguration. The cable actuation mechanism 110 includes a pair of pullcables 112, 114. The cable actuation mechanism 110 also includes a firstlinkage 116 that is used to rotate the articulated jaw 72 about thepivot pin 88 towards the clamped configuration, and an analogous secondlinkage 118 that is used to rotate the articulated jaw 72 about thepivot pin 88 towards the open configuration. The first linkage 116(shown in FIGS. 8A and 8B) includes a rotary link 120 that is mountedfor rotation relative to the end effector base 74 via a pivot pin 122. Aconnecting link 124 couples the rotary link 120 to the articulated jaw72 via a pivot pin 126 and a pivot pin 128. The first linkage 116 isarticulated via a pulling motion of the pull cable 112. In operation, apulling motion of the pull cable 112 rotates the rotary link 120 in aclockwise direction about the pivot pin 122. The resulting motion of theconnecting link 124 rotates the articulated jaw 72 in acounter-clockwise direction about the pivot pin 88 towards the clampedconfiguration.

The second linkage 118 (shown in FIGS. 8C through 8F) of the cableactuation mechanism 110 includes analogous components to the firstlinkage 116, for example, a rotary link 130 mounted for rotationrelative to the end effector base 74 via a pivot pin 132, and aconnecting link 134 that couples the rotary link 130 to the articulatedjaw 72 via two pivot pins 136, 138. The second linkage 118 isarticulated via a pulling motion of the pull cable 114. The secondlinkage 118 is configured such that a pulling motion of the pull cable114 rotates the articulated jaw 72 about the pivot pin 88 towards theopen configuration. In many embodiments, the pivot pin 136 between theconnecting link 134 and the rotary link 130 of the second linkage 118 is180 degrees out of phase with the pivot pin 126 between the connectinglink 124 and the rotary link 120 of the first linkage 116. Coordinatedpulling and extension of the pull cables 112, 114 of the cable actuationmechanism 110 is used to articulate the articulated jaw 72 between theopen and clamped configurations. In order to best provide equal andopposite cable motion (and thereby maintain cable tension in acapstan-driven system described below), a common rotational axis for thepivot pins 122, 132 is configured to lie on a plane that contains therotational axes for pivot pins 128, 138 when the articulated jaw 72 isclosed (or nearly closed) and again when the when the articulated jaw 72is open (or nearly open). The connecting links 124, 134 are assembledsymmetrically opposite about this same plane for the first and secondlinkages 116, 118. The distance between the pivot pins 122, 126 andbetween the pivot pins 132, 136 is the same for both the first andsecond linkages 116, 118, and the distance between the pivot pins 126,128 and between the pivot pins 136, 138 is the same for both the firstand second linkages 116, 118.

FIGS. 9A and 9B illustrate an articulation of the articulated jaw 72 viaanother cable actuation mechanism 140, in accordance with manyembodiments. In embodiment 140 of the cable actuation mechanism, a firstpull cable 142 and a second pull cable 144 are directly coupled with theproximal end of the articulated jaw 72. The first pull cable 142 wrapsaround a first pulley 146 so that a pulling motion of the first pullcable 142 rotates the articulated jaw 72 about the pivot pin 88 towardsthe clamped configuration. The second pull cable 144 wraps around asecond pulley 148 so that a pulling motion of the second pull cable 144rotates the articulated jaw 72 about the pivot pin 88 towards the openconfiguration. Accordingly, coordinated pulling and extension of thefirst and second pull cables of the cable actuation mechanism 140 isused to articulate the articulated jaw 72 between the open and clampedconfigurations. In order to best provide equal and opposite cable motion(and thereby maintain cable tension in the capstan-driven systemdescribed below), the radius of the arc prescribed by cable 142 aboutthe pivot 88 is substantially the same as the radius prescribed by cable144 about the pivot 88.

In many embodiments, the cable (i.e., low force) actuation mechanismcomprises a pair of pull cables that are actuated via an actuationfeature disposed in a proximal tool chassis. The proximal tool chassiscan be configured to be releasably mountable to a robotic toolmanipulator having a drive mechanism that operatively couples with theactuation feature. For example, the pair of pull cables can be wrappedaround a capstan located in the proximal tool chassis. The capstan canbe operatively coupled with a capstan drive servo motor of the robotictool manipulator when the proximal tool chassis is mounted to therobotic tool manipulator. Selective rotation of the capstan drive motorcan be used to produce a corresponding rotation of the capstan. Rotationof the capstan can be used to produce a coordinated extension andretraction of the pull cables. As discussed above, coordinated actuationof the pull cables can be used to produce a corresponding articulationof the articulated jaw of the end effector.

In many embodiments, the fast response/low force mode is provided by acable actuation mechanism that is back-drivable. For example, anexternal force applied to the articulated jaw can be used to rotate thearticulated jaw towards the clamped configuration and back-drive thecable actuation mechanism. With a cable actuation mechanism thatcomprises a pair of pull cables wrapped around a capstan, an externalforce that rotates the articulated jaw towards the clamped configurationproduces an increase in tension in one of the pull cables and a decreasein tension in the other pull cable, thereby causing the capstan torotate in response. As is known, such a cable driven system can beconfigured to have sufficient efficiency for back-drivability. Likewise,an external force applied to the articulated jaw can be used to rotatethe articulated jaw towards the open configuration and back-drive thecable actuation mechanism. As discussed above, a back-drivable fastresponse/low force actuation mechanism provides a number of benefits.

Alternate mechanisms can be used to provide a fast response/low forcearticulation mode. For example, an actuation mechanism comprisingpush/pull rods can be used.

FIG. 10 is a cross-sectional view illustrating components of the abovediscussed leadscrew actuation mechanism. The illustrated componentsinclude the leadscrew 82, the leadscrew driven cam 84, the cam slot 86in the end effector base 74, the distal journal surface 96, thecylindrical receptacle 154 in the end effector base, and the proximalbearing 98 supported by the end effector base 74.

FIG. 11 is a simplified perspective view diagrammatic illustration of atool assembly 170, in accordance with many embodiments. The toolassembly 170 includes a proximal actuation mechanism 172, an elongateshaft 174 having a proximal end and a distal end, a tool body 176disposed at the distal end of the shaft, a jaw 178 movable relative tothe tool body 176 between a clamped configuration and an openconfiguration, a first actuation mechanism coupled with the jaw, and asecond actuation mechanism coupled with the jaw. The first actuationmechanism is operable to vary the position of the jaw relative to thetool body between the clamped configuration and the open configuration.The second actuation mechanism has a first configuration where the jawis held in the clamped configuration and a second configuration wherethe position of the jaw relative to the tool body is unconstrained bythe second actuation mechanism. The first actuation mechanism isoperatively coupled with the proximal actuation mechanism. In manyembodiments, the first actuation mechanism comprises a pair of pullcables that are actuated by the proximal actuation mechanism. The secondactuation mechanism is operatively coupled with the proximal actuationmechanism. In many embodiments, the second actuation mechanism includesa leadscrew driven cam located in the tool body that is driven by theproximal actuation mechanism via a drive shaft extending through theelongate shaft 174164 from the proximal actuation mechanism.

The tool assembly 170 can be configured for use in a variety ofapplications. For example, the tool assembly 170 can be configured as ahand held device with manual and/or automated actuation used in theproximal actuation mechanism. The tool assembly 170 can also beconfigured for use in surgical applications, for example, electrocauterysealing, stapling, etc. The tool assembly 170 can have applicationsbeyond minimally invasive robotic surgery, for example, non-roboticminimally invasive surgery, non-minimally invasive robotic surgery,non-robotic non-minimally invasive surgery, as well as otherapplications where the use of the disclosed redundant jaw actuationwould be beneficial.

Redundant jaw actuation can be used to articulate a jaw of a robotictool end effector. For example, FIG. 12 schematically illustrates arobotic tool 180 employing redundant jaw actuation. The robotic tool 180includes a proximal tool chassis 182, a drive motor 184, an instrumentshaft 186, a distal end effector 188, a first actuation mechanismportion 190, and a second actuation mechanism 192. The distal endeffector 188 comprises an articulated jaw 194. The proximal tool chassis182 is releasably mountable to a robotic tool manipulator 196 having afirst drive 198, and a first actuation mechanism portion 200 thatoperatively couples with the first actuation mechanism portion 190 ofthe robotic tool 180 when the proximal tool chassis 182 is mounted tothe robotic tool manipulator 196. The instrument shaft 186 has aproximal end adjacent the tool chassis 182, and a distal end adjacentthe end effector 188. The first actuation mechanism (comprising portion200 and portion 190) couples the first drive 198 to the articulated jaw194 when the tool chassis 182 is mounted to the tool manipulator 196 soas to articulate the end effector 188 between an open configuration anda clamped configuration. The second actuation mechanism 192 couples thedrive motor 184 to the articulated jaw 194 so as to articulate the endeffector into the clamped configuration from the open configuration. Thefirst actuation mechanism can be a cable actuation mechanism, forexample, an above discussed cable actuation mechanism that provides thefast response/low force mode. In many embodiments, the first actuationmechanism is back-drivable. The second actuation mechanism can include adrive shaft that couples the drive motor 184 with a leadscrew actuationmechanism, for example, an above discussed leadscrew actuation mechanismthat provides the high clamping force mode. In many embodiments, thesecond actuation mechanism is non-back-drivable.

It is understood that the examples and embodiments described herein arefor illustrative purposes and that various modifications or changes inlight thereof will be suggested to persons skilled in the art and are tobe included within the spirit and purview of this application and thescope of the appended claims. Numerous different combinations arepossible, and such combinations are considered to be part of the presentinvention.

What is claimed is:
 1. A surgical method comprising: applying a graspingforce via a first actuation mechanism to tissue disposed between a jawand a treatment device of a surgical instrument; applying a clampingforce via a second actuation mechanism to the tissue disposed betweenthe jaw and the treatment device, the clamping force being greater thanthe grasping force; and treating the tissue while the clamping force isapplied to the tissue by actuating a third actuation mechanism.
 2. Thesurgical method of claim 1, wherein applying the grasping force to thetissue comprises retracting a first cable segment included in the firstactuation mechanism.
 3. The surgical method of claim 2, furthercomprising separating the jaw and the treatment device by retracting asecond cable segment included in the first actuation mechanism.
 4. Thesurgical method of claim 1, wherein: the second actuation mechanismcomprises a drive shaft and a cam translated via rotation of the driveshaft; and applying the clamping force to the tissue comprises rotatingthe drive shaft to translate the cam to generate the clamping force. 5.The surgical method of claim 4, wherein applying the clamping force tothe tissue comprises interfacing the cam with a proximal portion of thejaw disposed proximal to a jaw pivot point around which the jaw pivots.6. The surgical method of claim 1, wherein: the treatment devicecomprises a stapling device; the third actuation mechanism comprises asecond drive shaft drivingly coupled with the stapling device; andtreating the tissue comprises rotating the second drive shaft to staplethe tissue while the clamping force is applied to the tissue.
 7. Thesurgical method of claim 6, wherein: the treatment device comprises acutting device; and treating the tissue comprises rotating the seconddrive shaft to cut the tissue while the clamping force is applied to thetissue.
 8. The surgical method of claim 7, wherein the treatment devicecomprises a leadscrew rotated via rotation of the second drive shaft. 9.The surgical method of claim 1, wherein the clamping force is at least20 lbs.
 10. The surgical method of claim 1, wherein the treatment deviceis detachable.
 11. A surgical instrument comprising: an end effectorincluding a jaw and a treatment device; a first actuation mechanismdrivingly coupled with the end effector and operable to apply a graspingforce to a tissue disposed between the jaw and the treatment device; asecond actuation mechanism drivingly coupled with the end effector andconfigured to apply a clamping force to the tissue disposed between thejaw and the treatment device, the clamping force being greater than thegrasping force; and a third actuation mechanism drivingly coupled withthe treatment device and configured to treat the tissue while theclamping force is applied to the tissue.
 12. The surgical instrument ofclaim 11, wherein the first actuation mechanism comprises a first cablesegment drivingly coupled with the end effector to apply the graspingforce to the tissue via retraction of the first cable segment.
 13. Thesurgical instrument of claim 12, wherein the first actuation mechanismcomprises a second cable segment drivingly coupled with the end effectorto separate the first and second jaws via retraction of the second cablesegment.
 14. The surgical instrument of claim 11, wherein the secondactuation mechanism comprises a drive shaft and a cam translated viarotation of the drive shaft, the clamping force being generated viatranslation of the cam.
 15. The surgical instrument of claim 14, whereinthe cam is configured to be controllably interfaced with a proximalportion of the jaw disposed proximal to a jaw pivot point around whichthe jaw pivots.
 16. The surgical instrument of claim 11, wherein: thetreatment device comprises a stapling device; the third actuationmechanism comprises a second drive shaft drivingly coupled with thestapling device; and a rotation of the second drive shaft actuates thetreatment device to staple the tissue while the clamping force isapplied to the tissue.
 17. The surgical instrument of claim 16, wherein:the treatment device comprises a cutting device; and a rotation of thesecond drive shaft actuates the treatment device to cut the tissue whilethe clamping force is applied to the tissue.
 18. The surgical instrumentof claim 17, wherein the treatment device comprises a leadscrew rotatedvia rotation of the second drive shaft.
 19. The surgical instrument ofclaim 11, wherein the clamping force is at least 20 lbs.
 20. Thesurgical instrument of claim 11, wherein the treatment device isdetachable.